The majority of Keystone funding comes from Trans-Canada. They would be getting some subsidies in the neighborhood of 1.5 to 1.8 billion that anyone else building a pipe line qualifies for.There is a market for all grades of crude and Keystone will be capable of pumping more than just tar sand oil.
Trans-Canada can no longer afford to pay for the pipeline and the same is true of the Bakken field pipeline which is shorter and has higher quality oil and gas.
They can't afford it at $50 a barrel, but how long to you think Saudi Arabia can hold out flooding the market with cheap oil?
As long as it takes. Iraq owns 1/5 of the world's oil with some of the lowest marginal costs in the world as in less than $15/bbl for some of their fields. Drilling and recovery costs, real costs,.keep dropping as they have for more than 150 years. Alternative sources keep creeping towards parity with drilled oil placing a firm cap on how high oil can go. But that is simply the opinion of people who make their living selling oil.